1. Field of the Invention
The present invention relates to an earphone with an open-close type enclosure, and more specifically to an earphone in which it is possible to control the characteristics of the high-pitched and low-pitched tones of the sound waves progressing forward of the sound wave generation means, by controlling the opening and closing for a part of the enclosure, which is the housing enclosing the back of the sound wave generation means such as a speaker.
2. Description of the Related Art
In general, in the sound wave generation means such as a speaker, the vibration generated by the diaphragm is generated backward as well as forward. At this time, in order to improve the characteristics of the sound waves while making the sound waves progress forward only, an enclosure, which is a resonant chamber enclosing the music wave generation means, is provided in the back thereof.
This enclosure, which is also known as a cabinet, box, or the like, is a fixed shape housing enclosed airtightly by a wall formed of wood, metal, resin, or the like, and plays the role of confining, reflecting and amplifying the vibration generated backward of the sound wave generation means to send it forward. If sound waves are produced by operating only the sound wave generation means such as a speaker, the sound volume of low-pitched tones decreases remarkably and the tone quality of high-pitched tones decreases remarkably.
Conventionally, the enclosure was designed in a closed type of housing as much as possible. This is because the higher the sealability, the better the reflectivity and amplification degree of the vibration become.
For instance, Korean Patent Registration No. 10-0999321 discloses an airtight enclosure which is configured by an air cap 100 and a rear cap 200 that enclose a vibration space, which is the space in the back (the upper side in the drawing) of the speaker 700.
Meanwhile, a structure of an earphone, which is configured in such a way that the vibration space in the enclosure and the ambient air communicate at all times because a part of the enclosure is fixed in an open state, is known. This has an advantage of functioning in such a way that outer sounds such as a car horn transmitted from the ambient air are imported inside.
For example, Korean Patent Registration No. 10-1091560 disclose an enclosure which is configured by an upper cover 110 and an upper holder 130 that enclose the vibration space, which is the space in the back (the upper side in the drawing) of a speaker 150, and the vibration space communicates with ambient air at all times by sound exhaust apertures 111 and 131.
Depending on the kind of sound to be listened to, it is necessary to reinforce the high-pitched tones or the low-pitched tones. For instance, it is necessary to listen by reinforcing the high-pitched tones in the case of severe ambient noise, and listen by reinforcing the low-pitched tones in the case of well recorded classical music.
In the enclose disclosed in Korean Patent Registration No. 10-0999321, it is impossible to select high-pitched tones or low-pitched tones by the earphone function alone because the enclosure is completely closed at all times and is of an invariable structure. Further, in the enclose disclosed in Korean Patent Registration Gazette No. 10-1091560, it is impossible to select high-pitched tones or a low-pitched tones by the earphone function alone, since it is impossible to vary the reinforcement state of the high/low pitched tones determined by the size and position of the opened sound exhaust apertures 111 and 131, because the enclosure is open at all times and is of an invariable structure.